Local building codes and fire ordinances generally require buildings to be equipped with "EXIT" signs which are intended to assist the occupants of a building to find their way to the building's exits during an emergency. In most instances, the EXIT signs are illuminated so that they will be visible to the building's occupants in the event there is a power failure, thick smoke, or other condition in the building which impairs visibility. These signs typically are mounted above the exits in order to be visible from the largest possible area. Self-powered emergency lighting may also be provided to enable the occupants to find their way to an exit.
Unfortunately, in the event of an emergency in which visibility is impaired, these illuminated EXIT signs cannot always be seen. For instance, in the event of a power failure, the building may be too dark for the occupants to make their way to the vicinity of an exit where the EXIT sign would be visible. Other emergency situations involve the presence of smoke which ordinarily rises toward the ceiling, thus obscuring the EXIT sign even when an occupant is in the immediate vicinity of an exit. Furthermore, the illuminated EXIT signs and emergency lighting may fail, leaving the occupants of the building in complete darkness as they search for an exit out from the building.
One approach for directing occupants of a building to an exit when there is little or no available light has involved the use of photoluminescent materials. Such materials have been incorporated in photoluminescent paints, polymer webs, signs and the like which have been placed in factories, laboratories and other buildings to direct the occupants of those buildings to the nearest exit in the event of an emergency. While such systems may be effective, they are unattractive and have therefore been unacceptable for use in office buildings, hotels and other buildings in which aesthetically pleasing surroundings are an important concern.
In order to meet the demand for a photoluminescent system which is not aesthetically objectionable, but which is effective in directing the occupants of a building to the nearest exit in the absence of light, a carpet has been developed which incorporates photoluminescent fibers as part of the carpet pile. These fibers may be incorporated in the carpet pile in the form of direction-identifying indicia which, in the absence of light, point the occupants of a building in a particular direction toward an exit.
The aforementioned carpeting system has largely been unsuccessful. One problem with the system is that the photoluminescent fibers, having been woven to the carpet backing so as to project substantially perpendicular therefrom, emit a perceptible glow only from the exposed ends of the fibers. As a result, the carpet system emits only a faint glow which is difficult to see in partial or complete darkness. Also, with the carpet installed on the floor, the photoluminescent fibers become dirty and worn from pedestrian traffic, further attenuating the glow emitted by the fibers. Furthermore, once the glow emitted by the fibers has faded so as to no longer be visually perceptible, the direction-indicating indicia are no longer useful for directing the occupants of the building to the exits.
there therefore exists the need for a system which will reliably direct the occupants of a building to the nearest exit. Preferably, the system will be effective in normal light conditions, as well as in the event of a power failure, thick smoke or other situation resulting in partial or complete darkness. Still more preferably, the system will not detract from the aesthetic appearance of a building's interior in the normal day-today operation of the building.